Block molding machine



Oct 12, 1948. A. T. JOHNSON 2,451,167

BLOCK MOLDING MACHINE Filed June 3, 1947 3 Sheets-Sheet 1 7 I IN V ENTOR.

flrazken f r/bA/YJO/Y Z 7 BY Oct. 12, 1948. A, OHNSON 2,451,167

BLOCK MOLDING v MACHINE IN V EN TOR.

A TTO/FNEYJ et. 12, 1948. JQHNSON 2,451,167

BLOCK MOLDING MACHINE Filed June 3.- 1947 3 Sheets-Sheet I5 IN V EN TOR.

Patented Oct. 12, 1948 UNITED STATES PATENT OFFICE 2,451,167, BLOCKMOLDING MACHINE Andrew T. Johnson, Las Vegas, Nev. 7 Application June a,1947, Serial No. 752,119

Claims. 1 This invention relates to block molding machines, and moreparticularly to a machine for pressure-molding concrete building blocks.

A main object of the invention is to provide a novel and improvedconcrete block molding machine which is simple in construction, easy tooperate and reliable in performance. 7 A further object of the inventionis to provide an improved block molding machine of the hydraulicpressure type which is inexpensive to manufacture, sturdy inconstruction and Wherein the dimensions and texture of the product canbe accurately controlled.

Further objects and advantages of the invention will become apparentfrom the following description and claims, and from the accompanyingdrawings, wherein:

Figure 1 is a front elevational view, partly in cross-section of abuilding block molding machine constructed in accordance with thepresent invention.

Figure 2 is an enlarged side elevational View, partly in cross-section,of the top portion of the block molding machine of Figure 1.

Figure 3 is a top plan View of the main body of the machine of Figure 1illustrating the means employed therein for securing the core supportingframe therein.

Figure 4 is an enlarged front elevational detail view of the moldfilling box and its support ing' table, as employed in the machine ofFigure 1. a

Figure 5 is a front elevational view of the machine of Figure 1 showingits connections to a source of hydraulic fluid and pressure generatingmeans therefor as employed in the present invention.

Referring to the drawings, ll comprises the frame'of the machine, theframe consisting of longitudinal base channels l2 and transverse basechannels l3 rigidly secured together to define a rectangular bottomsupport for the machine, the channel flanges being directed outwardly,corner posts 14 secured to the inner corners of said bottom support andrising vertically therefrom, and a top rectangular'frame sectioncomprising longitudinal" channels i5, transverse channels i6 secured atits inner 'corners to the top portions of the posts I4. Connecting thebottom transverse channels I3 is a horizontal bottom plate member l! onwhich'is secured a pair of cylinders I8, I 8. Each cylinder has a topwall l9 which is formed at itscenter with a vertical bore Slidablyengaging the walls of each cylinder is a piston 2| having 2.

l5 and stem portion 22 vertically slidable in bore 20. Piston 2| andstem 22 are formed with a central vertical bore 23 in which is s-lidablypositioned a plunger rod 24 formed at its top end with an enlarged head25. Connected to the bottom wall of each cylinder 3 at its center is afluid inlet conduit 26, and connected to the junction of said conduitsis a common fluid supply pipe 21. Each cylinder is connected at itsupper wall portion to a vent chamber 28 having an air vent tube 29 and afluid overflow tube 30. Overflow tube 30 is connected to the fluidreservoir 3|, shown in Figure 5.

The upper portion of bore 23 is formed with an annular groove 32connected by a passage 33 in stem 22 to the lower outer portion of saidstem, said passage 33 opening into the upper portion of the cylinder [8when the parts are in the positions shown in Figure 1. A passage 34 inthe top wall member I9 connects the intermediate portion of bore 20 withthe top of the cylinder chamber 18 and is arranged so that when piston2i is raised by fluid pressure to its uppermost position in saidchamber, as determined by a stop shoulder 35 carried by said piston, thelower end of passage 33 registers with the upper end of passage 34. Thisby-passes any fluid which has leaked past'plunger bar 24 back to theupper portion of the main cylinder chamber. A stop screw 36 is providedin the bottom wall of each cylinder I8 for adjusting the lowermostposition of piston 2|.

Overlying and supported on the enlarged heads, 25, 25, is a bar member31 which is vertically movable, responsive to the upward movement ofsaid heads and is guided in its upward movement by vertical threadedbars 38 secured to the opposing horizontal flanges of the upper andlower transverse channel i6 and I3 and being slidably received innotches 39 formed inthe end portions of the bar member 31.

Stop nuts shown at 40 and 4| respectively limit the upward and downwardmovements of bar member 31, said stop nuts being threaded on thevertical bars 33 and being vertically adjustable thereon.

Secured in the top rectangular enclosure defined by the upperlongitudinal channels I5, I5 and the upper side channels I5 is arectangular box-like frame 42 which is open at its top and bottom and isprovided with transverse partitions 43, 43 dividing the frame into threeequal mold box compartments. The frame 42 is adjustably secured inposition by respective front and side clamping plates 44 and 45 engagedby clamping screws 46 threaded through the respective front channel I5and right side channel I6.

Secured to the bottom of the frame 42 by longitudinal bar elements 41are spaced core blocks 48, two such core blocks, being provided in eachmold box compartment. Overlying the end portions of the bar elements ineach mold box compartment and slidably fitting around the core blocksand inside the walls of the compartment is a push block. 49.] Overlyingthe push block is 'a pallet 50 on which the moldable material is adaptedto be deposited. Secured to the bottom of each push block 49substantially centrally As shown in Figure 5, 3| designatesthe fiuidreservoir. A conduit 66 connects reservoir 3| to a pump 61. The outletconduit '68 of said pump is connected through an accumulator tank 69 toa conduit 10. Conduit is connected to conduit 21 through a valve IIwhich'is manually controlled by a valve rod I2. 1 Also connected toconduit 21 is an exhaust pipe 13 opening in reservoir I 31, said exhaustpipe including a valve 14 which thereof and depending therefrom is avertical;

push rod 5| provided at its bottom end with an adjustable stop screw 52.The push rodsfi'lslid ably pass through a horizontal guide plate 53secured to the frame II, said guide plate having upstanding guidecollars 54 encircling the respec-' tive push rods '5I. Subadjacent thestop screws 52 :is the pressure equalizing bar'3I against which thepistonheads '25 bear upwardly whenfluid underpressure is introduced intothe cylinders I8. Bar 31 is freely vertically movable within the frameand is formed with the guide notches 39, as above described, cooperatingwith the vertical guide bars-38. 1 r

' Pivotally secured to the top transverse side edge of the frame I I byatransverse hinge-1311155 is'atop cover plate 56 provided with acounterweight 5'! to facilitate opening the cover plate. Pivoted to theopposite free edge portion of the cover plate is a latch 58 adapted tohook under thetop ,fiange of the adjacent side channel IIB to lock thecover plate in closed position. The. cover plate carries .on its bottomsurface pressure lugs 59 fitting around'the core blocks 48 in the spacebetween said blocks and the mold box walls. Secured to the rear toplongitudinal channel l5 by triangular gussets 60 is a rearwardlyextending horizontal table plate 6| substantially flush with the topflange surfaces ofthe channels I5, I5; The table plate is :formed withparallel transverse guide channels "62; 62 and slidably engaged thereinare the lateral'ribs 63, 63 carried by a box member 64 'which'is therebytransversely slidable on table plate 6 I Box mem ber 64 has sidehandles65', 65 for manipulating the'box'member backwardly and forwardlyw'lthrespect to the guide channels 6 2, 62. The bottom and top of the boxmember 64 are-open. "In charging the mold box compartment,'box member 64is first positioned on table plate BI in the position shown in Figure 2and is filled with the moldable material; With the push rods :5I in depressed positions, as shown in Figure 1, the box member 64 is then movedforwardly until it over} lies the mold box compartments; whereby themoldable material drops into said compartments. The box member 64 isthen moved back rear- Wardly of its starting position, whereby excessmoldable material is struck off from the top of the mold boxcompartments. The inoldbox com-v partments arethen ready for the moldingoperation.

In molding the blocks, the cover member 55 is swung to closed positionand latched thereini Lugs 59 act to tamp the moldable materialdownwardly somewhat preliminary to the actual appli cation of moldingpressure. With covermember 56 locked in closed position, fluid underpressure is admitted to cylinders I8 through conduits 26, causing themain pistons 2| to rise, upward force being transmitted at heads 25 tothe equalizer bar is manually controlled by a valve rod I5. Con-. nectedahead of valve II to conduit 10 is a conduit 16 opening into reservoir3I and including a relief valve 11 adapted to open when the pressure inconduit I0 rises to a limit value substantially Wall of the cylinder.

higher than the working pressure value. The conduit connecting tank' 69to conduit I0 includes amanual shut-off valve 18. Ajby-Passconduit '19connects conduit 58 to conduit Illand includes a manual shut-off .valve80. By closingnzeiither Valve 80 orvalve I8, either -by.-pass;conduit T9orlaccumulator tanks-9 may be excluded-from the. fluid pressure line.When tank 59: is emf;

ployed, it acts to accumulate a large, amount of fluid under pressure inthe fluid-supply system and substantially eliminates pressurefluctuations inthe'fluidpressure line.

In order tocompress the moldable materiaLas' above described, valve I4is closed and'valve II. is opened, so that fluid underpressurefentersthe cylinders IB, Piston .ZI in each cylindermoves upwardly untilshoulder35 thereof abuts the'top At this point valve His closedmomentarily and cover ,member is une; latched and raised to a vertical.positiom -being held therein by the counter-weight 51.. Valve "II isagain opened, and plunger 24 of each cylinder is forced upwardly by theadditional fluid under pressure entering the cylinders. Equalizer. barl31 is moved upwardly until further. upwardmovee ment thereof is:prevented by the stoplinutsifll. This elevates the push blocks 49and'raisesthe' formed blocks out of the mold box compartments; thepushblocks being finally in positions suchas shown in Figure 2.

Secured tothe front wall of the box member 64 is a forwardly projectinghorizontal'lug BI"; .To' receive a new charge of moldable material, boxmember 64 is moved forwardly until its "bottom forward edge portion 82abuts the adjacent t'op edge portions .of the push blocks 49. Thelugflby this motion moves overthetop surface ofthe .push blocks and pushesthepallet-me'mbersfifl carrying the finished blocks 83 forwardly/"sovthat the pallet members and finished-blocks may bere- 1 When unloadingis 7 moved from the machine. 7 completed, valve .II is closed and valve1441's opened, .allowingthe fluid in the cylinders .I8 to" exhaust intothe reservoir 3 I and allowin the Dis;v tons therein to return to theirstartin positions: and the push blocks 49 to drop back to'theirbot tompositions in the mold box compartments. New pallets are then insertedthereonand-the process may be repeated' The machine is not limited tothe boxes illustrated and described above. Any size and shape of moldbox and corresponding pressure:

transmitting members therefor may be employed.

in place of the frame 42 and its associatedpre sure transmittingcomponents.

The. length of the power stroke and the raising stroke may be readilyadjusted, by .respec tively adjusting the stop screws 36 and the stopnuts 40 and 4 l. The depression of equalizer member 13 is limited by theadjustment of lower stop nuts 4|, thus controlling the amount ofmaterial that can be placed in the mold box compartments beforecompression.

By the above described adjustments the power stroke and the subsequentblock ejection stroke of the respective pistons 2| and 24 can becontrolled within very exact limits.

Accurate sizing is obtained on all exterior and interior surfaces of thefinished blocks due to the smooth vertical surfaces employed on the moldbox walls and cores and the polishing action produced on the blocksduring the process of upward ejection of the blocks along said smoothvertical surfaces.

The equalizer bar 3'! insures that the compressive load will be equallydistributed on the heads 25 and that said heads will advance in unisonduring the compression stroke. If one piston advances faster than theother the bar 31 tilts and engages the edge portions of the piston heads25. This causes the leading piston to immediately assume more than itsnormal proportion of load, and since both pistons are of equal size andare actuated by a common pressure source, the piston carrying the reaterload will be retarded until the other piston advances to the point wherethe bar 31 will return to horizontal position across the wide faces ofthe piston heads. From this point the pistons will again advance inunison.

The use of the energy-storing accumulator tank 69 makes it possible toemploy a relatively small capacity pump 61.

While a specific embodiment of a block molding machine has beendisclosed in the foregoing description, it will be understood thatvarious modifications within the spirit of the invention may occur tothose skilled in the art. Therefore, it is intended that no limitationsbe placed on the invention other than as defined by the scope of theappended claims.

What is claimed is:

l. A pressure molding machine for forming building blocks comprising arectangular box-like frame, a pair of cylinders secured vertically inthe lower portion of the frame, a main piston in each cylinder, anauxiliary piston telescoped in said main piston and vertically slidabletherein, the main piston having a stem portion slidably fitting the topwall of the cylinder, an enlarged head on the top end of each auxiliarypiston, a bar member overlying the piston heads, means guiding said barmember for vertical movement, a mold box secured in the upper portion ofthe frame, an upwardly movable plunger slidably fitting said mold box,and a depending vertical push rod carried by said plunger and engagingthe bar member at its bottom end.

2. A block molding machine comprising a rectangular box-like frame, avertical cylinder secured in the lower portion of the frame, a mainpiston in said cylinder having a stem passing slidably through the topwall of said cylinder, an auxiliary piston telescoped in said mainpiston and stem and vertically slidable therein, an enlarged head on thetop end of said auxiliary piston, a pressure transmitting memberoverlying said head, a mold box secured in the upper portion of theframe, a releasable closure for the top of said mold box, an upwardlymovable plunger slidably fitting said mold box and defining a bottomclosure therefore, and a depending rod member carried by said plungerand engaged at its bottom end with said pressure-transmitting member,

3. A block molding machine comprising a rectangular box-like frame, apair of vertical cylinders secured in the lower portion of said frame, amain piston in each cylinder having a stem passing slidably through thetop wall of said cylinder, an auxiliary piston telescoped in each mainpiston and stem and vertically slidable therein, an enlarged head on thetop end of each auxiliary piston, a tiltable bar supported on saidenlarged heads, a mold box secured in the upper portion of the frame, areleasable top closure for said mold box carried by said frame, avertically movable plunger slidably fitting said mold box and defining abottom closure therefor, and a depending rod member rigidly secured tosaid plunger and engaging the tiltable bar at its bottom end.

4. A block molding machine comprising a reco tangular box-like frame, apair of vertical cylinders secured in the lower portion of said frame, amain piston in each cylinder having a stem pass ing slidably through thetop wall of said cylinder, an auxiliary piston telescoped co-axially ineach Of said main pistons and vertically slidable therein, a tiltablebar supported on the top ends of the auxiliary pistons, means carried bythe frame for guiding said tiltable bar for vertical movement, a moldbox secured in the upper portion of the frame, a releasable top closurefor said mold box pivotally secured at one end to a top edge of theframe, a vertically movable plunger slidably fitting said mold box anddefining a bottom closure therefor and a depending rod member rigidlysecured to said plunger and engaging the tiltable bar at its bottom end.

5. A block molding machine comprising a rectangular box-like frame, apair of vertical cylinders secured in the lower portion of said frame, amain piston in each cylinder having a stem pass ing slidably through thetop wall of said cylinder, an auxiliary piston telescoped coaxially ineach of said main pistons and vertically slidable therein, a tiltablebar supported on the top ends of the auxiliary pistons, means carried bythe frame for guiding said tiltable bar for vertical movement, saidmeans being adapted to limit the range of vertical movement of said bar,a mold box secured in the upper portion of the frame, a top closure forsaid mold box hinged to a top edge of the frame, a vertically movableplunger slidably fitting said mold box and defining a bottom closuretherefor, a depending rod member rigidly secured to said plunger andengaging the tiltable bar at its bottom end, a horizontal supportcarried by said frame adjacent the top edge of said mold box, a pair ofparallel guide rails on said support, a shell member slidably engagedwith said guide rails and slidable on said support to a positionoverlying the mold box, and a forwardly projecting horizontal flangecarried at the forward wall of said shell member.

ANDREW T. JOHNSON.

N 0 references cited.

